Means for operating elevator-doors



(No Model.)

7 L. PREAS.

MEANS FOR OPERATING ELEVATOR DOORS. No 503,345.

Patented Aug 15, 1893.

g -INVENTOR WITNESSES a r I W UNITED STATES PATENT OFFICE.

LOUIS FREAS, OF PITTSBURG, PENNSYLVANIA.

M EANS FO R OPERATING ELEVATO R-DOO RS.

SPECIFICATION forming part of Letters Patent No. 503,345, dated August15, 1893.

Application filed April 11, 1893. Serial No. 469,899- (No model.)

To all whom it may concern.-

Be it known that I, LOUIS FREAS, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Elevator-Doors, of which the following is a full, clear,and exact description, reference being had to the accompanying drawings,forming part of this specification, in Which- Figure 1 is a frontelevation of an elevator hatch door, constructed in accordance with myinvention. Fig. 2 is a side elevation thereof, showing the elevator inthe act of releasing the catch by which the door is held open. Fig. 3 isa horizontal section on the line IIIIII of Fig. 1.

Like symbols of reference indicate like parts in each The object of myinvention is to provide simple and efitective means for operatingelevator doors, adapting them to close automatically as the elevator-carleaves the floor at which the door is located.

In the drawings, 2 represents the door,which slides back and forth infront of the hatch, in the usual manner.

3 is a weight connected with the door by a flexible connection at, andadapted to draw the door to a closed position as shown in Fig. 1. Aspring may be substituted for the weight.

5 is a pivoted latch or trigger-lever having a notch 1) adapted toengage a projection 6 at one edge of the door to hold it open, or acorresponding projection 7 at the other edge of the door to hold itshut. The shoulder which forms the inner end of the notch is madesomewhat less prominent than the outer shoulder, for a purposehereinafter explained.

8 is a spring which tends to force the latch into locking position.

9 is a cam surface on the elevator car, arranged in such position thatwhen the car reaches the floor it will engage the latch and retract it.This cam has two prominent portions 0 and d and an intermediate lessprominent portion 6.

The operation is as follows :V\ hen the bottom of the car comes nearlyto the level of the floor, the cam engages the latch, and when the caris at the floor-level the portion 6 of the cam is in contact with thelatch, and holds the same in such position that the less prominentshoulder of the notch b is released from the projection 7, thus leavingthe door free to be moved back on its slide into open position. When thedoor has been opened, the more prominent of the shoulders of the notch12 engages the projection 6 and holds the door open, for the part c ofthe cam does not retract the latch sulficient-ly to render this shoulderinoperative. When the elevator leaves the floor, either in ascending ordescending, the more prominent portion 0 or d of the cam engages thelatch, and retracts it sufficiently to disengage it from the projection6, whereupon the weight 3 immediately draws the door shut, and when ithas been moved thereby into the position shown in Fig. 1, the latch,being freed from the cam, springs into engagement with the projection 7,and holds it locked.

By means of my improvement the safety of operating the elevator is verymuch enhanced; the device is simple, effective, and is not apt to getout of order.

Various modifications in the form and relative arrangement of the partsof the device may be made without departure from my invention as definedin the claim.

I claim- The combination with an elevator door, of a latch adapted toengage the door at the front and rear edges thereof, and a cam on theelevator car having two outer projections and an intermediate projectionof diiferent degree of prominence, said cam being adapted to engage thelatch and to operate it when the elevator reaches the floor or landing;said latch having holding-portions of dilterent degrees of prominenceadapted to be brought successively into action by operation of the cam;substantially as described.

In testimony whereof I have hereunto set my hand.

LOUIS FREAS.

YVitnesses:

THOMAS W. BAKEWELL, W. B. CORWIN.

